| Physiological response of different salt-tolerant apple rootstocks to salt stress |
|
View Fulltext View/Add Comment Download reader |
| |
| DOI：10.7606/j.issn.1000-7601.2021.04.11 |
| Key Words: apple rootstock salt stress physiological response photosynthetic fluorescence antioxidant enzymes osmotic adjustment |
| Author Name | Affiliation | | ZHANG De | College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730030, China | | ZHANG Rui | College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730030, China | | ZHANG Xiayi | College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730030, China | | WU Yuxia | College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730030, China | | ZHAO Ting | College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730030, China | | ZHANG Zhongxing | College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730030, China | | WANG Shuangcheng | College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730030, China | | WANG Yanxiu | College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730030, China |
|
| Hits: 639 |
| Download times: 133 |
| Abstract: |
| This study was to explore the effect of salt stress on the physiological characteristics of two apple rootstocks of Malus halliana Koehne and Malus baccata Borkh with different resistance, and to analyze the salt tolerance mechanism of Malus resources. One\|year\|old M. halliana ‘9-1-6’ and M. baccata were used as experiment materials. The photosynthetic fluorescence parameters, antioxidant enzymes and osmotic adjustment substance content were measured using potting with Hogland nutrient solution under 100 mM NaCl short\|term (3 d) and long\|term (40 d) stress and physiological differences of different resistant apple rootstocks in response to salt stress were analyzed. The results showed that salt stress significantly reduced leaf net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), maximum light energy conversion rate (Fv/Fm), actual photochemical efficiency (ΦPSⅡ) and photochemical quenching coefficient (qP), which in turn increased the intercellular CO2 concentration (Ci), initial fluorescence (F0), non\|regulatory energy dissipation (Y(NO)) and non\|photochemical quenching coefficient (qN). There were no significant difference between the two rootstocks of Tr under salt stress, but Pn, Gs, Fv/Fm, ΦPSⅡand qP of ‘9-1-6’ were significantly higher than those of M. baccata, compared with CK, Pn, Gs, Fv/Fm, ΦPSⅡ and qP of ‘9-1-6’ leaves decreased respectively by 58.4%, 57.90%, 12.90%, 67.00% and 48.60%, while those of M. baccata were 91.90%, 82.4%, 83.90%, 84.20% and 76.40%, respectively. The Ci, F0, Y(NO) and qN of ‘9-1-6’ leaves were 0.76, 0.78, 0.61 and 0.82 times as much as those of M. baccata, respectively. The photosynthetic electron transport rate (ETR) of ‘9-1-6’ increased first and then decreased, while the ETR of M. baccata continued to decline. The change range of the resistant rootstock M. halliana ‘9-1-6’ was less than that of the sensitive rootstock M. baccata. Under salt stress, the activities of ‘9-1-6’ leaf superoxide dismutase (SOD), superoxide dismutase (POD) and ascorbate oxidase (APX) all showed a same trend of first increasing and then decreasing, which were respectively 1.33, 1.38, and 1.23 times of M .baccata. ‘9-1-6’ regulatory energy dissipation (Y(NPQ)) and proline (Pro) content continuously increased by 158.0% and 87.9% respectively in comparison to CK. While the M. baccata continued to decline, they were 69.4% and 69.2% of CK respectively. The content of ascorbic acid, sucrose and sorbitol of M. halliana ‘9-1-6’ leaves significantly higher than that of M. baccata. Compared with CK, the content of ‘9-1-6’ of these three items increased by 49.8%, 39.9% and 36.2%, and for M. baccata, the numbers were 50.2%, 23.4% and 18.5%. The hydrogen peroxide (H2O2) content of ‘9-1-6’ leaves was significantly lower than that of M. baccata, which was only 82.6%. Through self\|regulation of photosynthetic mechanism, M. halliana ‘9-1-6’ of high salt\|tolerant apple rootstock maintained high Pn and Fv/Fm, accumulated osmotic adjustment substances (sucrose, sorbitol and Pro), regulated the osmotic balance of cells, and increased antioxidant enzymes (APX, SOD, POD) activity so as to effectively remove ROS and keep the membrane system relatively stable. This self\|regulation was an important physiological mechanism for its response to salt stress. |
|
|
|